tetano
Editor, Senior Moderator
Vaccine. 2014 Mar 5. pii: S0264-410X(14)00141-8. doi: 10.1016/j.vaccine.2014.01.078. [Epub ahead of print]
Stability of neuraminidase in inactivated influenza vaccines.
Sultana I1, Yang K1, Getie-Kebtie M2, Couzens L1, Markoff L1, Alterman M2, Eichelberger MC3.
Author information
Abstract
Influenza vaccines are effective in protecting against illness and death caused by this seasonal pathogen. Antibodies that block the function of either hemagglutinin (HA) or neuraminidase (NA) contribute to vaccine efficacy, however vaccine potency is based only on HA content. NA protein content in vaccines varies from season to season due to differences in the relative amounts of HA and NA in influenza A, H1N1 and H3N2, and influenza B viruses that are selected for each manufacturing campaign. This, as well as potential inherent differences in NA immunogenicity, may result in varying responses from year to year. Moreover, the antigenic stability of NAs in a vaccine is likely to dictate whether similar antibody responses will be obtained to this antigen throughout the shelf-life of the vaccine. To address this factor, we subjected NAs of influenza A (subtypes N1 and N2) and B viruses to denaturing conditions to evaluate the stability of enzyme activity. Each NA type/subtype had unique sensitivity to denaturing conditions. The N2 enzyme activity was more thermostable than that of N1 or influenza B, while the NA activity of influenza B was most resistant to detergent and N1 enzyme activity was most resistant of the three viruses to freeze-thaw cycling. In these experiments, enzyme activity was indicative of the immunogenicity of NA, with loss of enzyme activity and immunogenicity following repeated freeze-thawing. Immunogenicity was strain-dependent, with greater neuraminidase inhibiting (NI) antibody titers elicited following immunization with the 2009 H1N1 pandemic virus A/California/7/2009, than the previously circulation seasonal strain, A/Brisbane/59/2007. Robust NI antibody titers against both N1 and N2 components were induced following vaccination of mice with a trivalent inactivated influenza vaccine. When stored under recommended conditions, the NA of both N1 and N2 subtypes remained immunogenic well after the vaccine expiry date.
Copyright ? 2014. Published by Elsevier Ltd.
KEYWORDS:
Immunogenicity, Influenza, Neuraminidase, Stability, Vaccines
PMID:
24613525
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/24613525
Stability of neuraminidase in inactivated influenza vaccines.
Sultana I1, Yang K1, Getie-Kebtie M2, Couzens L1, Markoff L1, Alterman M2, Eichelberger MC3.
Author information
Abstract
Influenza vaccines are effective in protecting against illness and death caused by this seasonal pathogen. Antibodies that block the function of either hemagglutinin (HA) or neuraminidase (NA) contribute to vaccine efficacy, however vaccine potency is based only on HA content. NA protein content in vaccines varies from season to season due to differences in the relative amounts of HA and NA in influenza A, H1N1 and H3N2, and influenza B viruses that are selected for each manufacturing campaign. This, as well as potential inherent differences in NA immunogenicity, may result in varying responses from year to year. Moreover, the antigenic stability of NAs in a vaccine is likely to dictate whether similar antibody responses will be obtained to this antigen throughout the shelf-life of the vaccine. To address this factor, we subjected NAs of influenza A (subtypes N1 and N2) and B viruses to denaturing conditions to evaluate the stability of enzyme activity. Each NA type/subtype had unique sensitivity to denaturing conditions. The N2 enzyme activity was more thermostable than that of N1 or influenza B, while the NA activity of influenza B was most resistant to detergent and N1 enzyme activity was most resistant of the three viruses to freeze-thaw cycling. In these experiments, enzyme activity was indicative of the immunogenicity of NA, with loss of enzyme activity and immunogenicity following repeated freeze-thawing. Immunogenicity was strain-dependent, with greater neuraminidase inhibiting (NI) antibody titers elicited following immunization with the 2009 H1N1 pandemic virus A/California/7/2009, than the previously circulation seasonal strain, A/Brisbane/59/2007. Robust NI antibody titers against both N1 and N2 components were induced following vaccination of mice with a trivalent inactivated influenza vaccine. When stored under recommended conditions, the NA of both N1 and N2 subtypes remained immunogenic well after the vaccine expiry date.
Copyright ? 2014. Published by Elsevier Ltd.
KEYWORDS:
Immunogenicity, Influenza, Neuraminidase, Stability, Vaccines
PMID:
24613525
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/24613525